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* [PATCH] drm/amdgpu: Avoid integer overflow in amdgpu_device_suspend_display_audio
@ 2020-05-02  3:11 Nathan Chancellor
  2020-05-05 14:44 ` Alex Deucher
  0 siblings, 1 reply; 2+ messages in thread
From: Nathan Chancellor @ 2020-05-02  3:11 UTC (permalink / raw)
  To: Alex Deucher, Christian König, David (ChunMing) Zhou
  Cc: amd-gfx, dri-devel, linux-kernel, clang-built-linux, Nathan Chancellor

When building with Clang:

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:4160:53: warning: overflow in
expression; result is -294967296 with type 'long' [-Winteger-overflow]
                expires = ktime_get_mono_fast_ns() + NSEC_PER_SEC * 4L;
                                                                  ^
1 warning generated.

Multiplication happens first due to order of operations and both
NSEC_PER_SEC and 4 are long literals so the expression overflows. To
avoid this, make 4 an unsigned long long literal, which matches the
type of expires (u64).

Fixes: 3f12acc8d6d4 ("drm/amdgpu: put the audio codec into suspend state before gpu reset V3")
Link: https://github.com/ClangBuiltLinux/linux/issues/1017
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 6f93af972b0a..caa38e7d502e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4157,7 +4157,7 @@ static int amdgpu_device_suspend_display_audio(struct amdgpu_device *adev)
 		 * the audio controller default autosuspend delay setting.
 		 * 4S used here is guaranteed to cover that.
 		 */
-		expires = ktime_get_mono_fast_ns() + NSEC_PER_SEC * 4L;
+		expires = ktime_get_mono_fast_ns() + NSEC_PER_SEC * 4ULL;
 
 	while (!pm_runtime_status_suspended(&(p->dev))) {
 		if (!pm_runtime_suspend(&(p->dev)))

base-commit: fb9d670f57e3f6478602328bbbf71138be06ca4f
-- 
2.26.2


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] drm/amdgpu: Avoid integer overflow in amdgpu_device_suspend_display_audio
  2020-05-02  3:11 [PATCH] drm/amdgpu: Avoid integer overflow in amdgpu_device_suspend_display_audio Nathan Chancellor
@ 2020-05-05 14:44 ` Alex Deucher
  0 siblings, 0 replies; 2+ messages in thread
From: Alex Deucher @ 2020-05-05 14:44 UTC (permalink / raw)
  To: Nathan Chancellor
  Cc: Alex Deucher, Christian König, David (ChunMing) Zhou,
	clang-built-linux, Maling list - DRI developers, amd-gfx list,
	LKML

On Sat, May 2, 2020 at 4:35 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> When building with Clang:
>
> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:4160:53: warning: overflow in
> expression; result is -294967296 with type 'long' [-Winteger-overflow]
>                 expires = ktime_get_mono_fast_ns() + NSEC_PER_SEC * 4L;
>                                                                   ^
> 1 warning generated.
>
> Multiplication happens first due to order of operations and both
> NSEC_PER_SEC and 4 are long literals so the expression overflows. To
> avoid this, make 4 an unsigned long long literal, which matches the
> type of expires (u64).
>
> Fixes: 3f12acc8d6d4 ("drm/amdgpu: put the audio codec into suspend state before gpu reset V3")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1017
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

Applied.  Thanks!

Alex

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 6f93af972b0a..caa38e7d502e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -4157,7 +4157,7 @@ static int amdgpu_device_suspend_display_audio(struct amdgpu_device *adev)
>                  * the audio controller default autosuspend delay setting.
>                  * 4S used here is guaranteed to cover that.
>                  */
> -               expires = ktime_get_mono_fast_ns() + NSEC_PER_SEC * 4L;
> +               expires = ktime_get_mono_fast_ns() + NSEC_PER_SEC * 4ULL;
>
>         while (!pm_runtime_status_suspended(&(p->dev))) {
>                 if (!pm_runtime_suspend(&(p->dev)))
>
> base-commit: fb9d670f57e3f6478602328bbbf71138be06ca4f
> --
> 2.26.2
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

^ permalink raw reply	[flat|nested] 2+ messages in thread

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